As we look toward a future with mandatory Green Building Ordinances in California and elsewhere, one critical construction component is often overlooked – – site preparation. Regardless of the site – whether there is a pre-existing structure or simply an open field – site preparation typically signals the start of the actual construction process.
The conventional way to bring down a building is the good ol’ wrecking ball. The building is collapsed into a huge pile of rubble and then transferred to commingled debris dumpsters. All materials are lumped together, many of which take several generations to decompose. Steel – 100 years. Aluminum – 300 years. Plastic – 450 years. Glass never decomposes. Then there is the hazardous waste – – who knows that harm is lurking there. Regardless, this conventional, commingled trash heap isn’t going anywhere soon because, no matter the nature of the material, it is all going to the same place – landfill.
There is a better way.
Thankfully, the easy alternative is “green” site preparation. Sure it takes a little more planning and coordination but really it just comes down to thoughtful deconstruction, site-sorting, and mindful demolition. With some foresight and creativity, landfill becomes the last option for site preparation by-products. Instead, the lifecycle of the by-products is extended… and everyone wins… and you might even get a tax break for your green efforts.
This life-cycle extension is at the core of one facet of sustainability that we strive to practice in all we do… cradle to cradle construction. The materials that are “born” to build one structure are recaptured via mindful demolition and “reborn” by reuse or recycling.
To illustrate the difference between the conventional wrecking ball method and a more environmentally-positive approach, I will share a little about my experiences managing deconstruction projects in California. In each instance, LEED Materials & Resources was used as a guide, a landfill diversion rate of at least 75% always the goal. eco-Organize has proudly achieved a more than 82% diversion rate on all of its projects, the highest rate to date being 99.2%.
How is this possible? The answer is fairly easy albeit systematic.
As background, landfill diversion simply means keeping things out of landfill – – be it by reuse, recycling, or repurposing. Moreover, there are two basic steps to the diversion process: Deconstruction and demolition. Any hazardous waste abatement happens beforehand.
Deconstruction has two distinct phases. First is the soft-strip where the structural interior and exterior are scoured for reusable and recyclable materials. Reuse should always be the paramount goal, whether the materials are to be reused on-site as part of the new project or integrated somewhere off-site. During this phase, items like reclaimed wood, brick, and rock and reusable or recyclable fixtures and furniture are extracted. By the time this first phase is complete, there should be nothing much left but the structural envelope i.e, walls, roof, and foundation and supporting members.
The envelope is demolished in the second phase. Here, all the remaining debris is site-sorted, meaning things like /rebar are separated from concrete, clean wood studs are separated from drywall, lathe separated from plaster. Once demolition is complete, there is an assortment of piles i.e., clean wood, drywall, metal. All materials from both phases are parsed out and inventoried. These materials are then transferred by material type to a reuse or recycling facility for processing. Achieving the aforementioned 99.2% landfill diversion rate meant that some 382,220 lbs or 191 tons of debris was reused or recycled, while 3,020 lbs (or a mere 1.5 tons) amounted to strictly waste and was sent to landfill because there was simply no another option. The materials sent to landfill included things like insulation and carpeting, which in some other jurisdictions are also recyclable.
To put this in perspective, the demolition of a typically 2,500 square foot home can produce over 25 tons of debris.
You likely are intrigued and, hopefully, inspired by this tremendous result. However, you are also likely asking – “Yeah, but at what additional cost?” Amazingly, the cost differential was minimal. It could have been even more cost-effective in an area with a better variety of recycling and reuse options.
For this project, I teamed up with demolition contractor Mark Dixon – of Middleton, California. Mark says “it took a little more time but my profit margin was about the same.” For this particular project, Mark calculated that the difference between what it would have cost to do this project the traditional way versus the actual greener approach were “real close.” The main point – There was a nominal increase to achieve an amazing result.
Disposal costs do vary from jurisdiction to jurisdiction. For instance, had this project been in a city just 20 miles south, approximately 50% would have been saved on the cost of dumpsters alone. This would have actually increased Mark’s profit.
Between the disposal costs savings and potential money to be made in the reusable building materials market, the monetary advantages of green demolition become easily evident.
But wait, there’s more. There may be an opportunity for a tax donation benefit for reusable materials. Vierra Environmental Consulting works with our clients to explore all opportunities to make green and sustainable practices easy and affordable, if not profitable. Typically, the generated cost-savings covers Vierra Environmental Consulting’s services and more.
To bring these projects full circle, you are probably wondering how the demolition debris is escaping landfill. Here’s the scoop. If it’s reusable, it’s reused – either on the existing project or donated for use on some other. As for recyclables – Concrete and asphalt become gravel, dirt is used for topsoil and fill, yard waste is turned into organic compost, wood is sent to a biomass energy facility, and metal, cardboard, paper, plastic, and glass are recycled into a wide range of new materials. New technologies and domestic uses for discarded building materials are on a rapid rise in the United States. As after-market options increase, costs will continue to fall. The bottom line: All of this effort is having a significant impact in our fight against global warming… while saving consumers money and creating jobs.
With the guidance of an experienced project manager well-versed in landfill diversion options and best practices for sequencing you too can experience amazing results, saving money and time, and in turn benefiting your neighbors and our protecting our planet.
© 2010, Toni Renee Vierra. All rights reserved. Do not republish.